This invention relates to a closure for consumer containers as may be used to package spices, sugar, powdered drink mixes, salt or other dry, fluent (flowable) materials or products. More specifically, this invention relates to such a closure which may be used with small containers with a flip open lid that exposes one or more product dispensing holes through which the product may be poured, shaken or spooned from the container.
In the high-speed packaging of dry, fluent products, a pre-measured quantity (either a pre-determined weight or volume) of the product is discharged into the container. Oftentimes, a tamper-evident, tear-off seal is adhered to the mouth of the container after filling of the container. These containers typically have a screw-on closure which is threaded onto the threaded neck of the container by high-speed capping equipment incorporated in the product filling line. Such capping equipment oftentimes applies more torque to the closure than is necessary to insure that the closure is tightly screwed onto the container. In the past, this excess torque applied to the closure caused the closure to deform as it was screwed tightly to the container, which, in turn, caused a flip open lid formed with the closure to become unseated from the remainder of the closure and to partially open or to open. With the lid in a partially open position, the container could become jammed in the filling line, or the partially open lids would not allow the containers to be packaged in overcartons using automated equipment. In addition, such partially open lids may cause the filled package to be automatically rejected by the filling line or by inspectors. Still further, even if the lid would remain closed during filling and packing in overcartons, the stress imposed on the closure during the capping operation would, on occasion, cause the flip open lids to become unseated during shipping or while the container was on a store shelf prior to being purchased by a consumer. Such partially open lids would cause the container to be seen by the store clerks or the consumer as defective because the clerk or the consumer may believe that the product had been opened or contaminated, even though a taper-evident seal applied to the mouth of the container under the closure remained intact. As will be appreciated, such containers having the above-described tamper-evident seals applied to the mouth of the container must be removed prior to use by unscrewing the closure from the container, removing the seal, and then screwing the closure back onto the container. On occasion, the consumer (customer) may, when using the container, over-tighten the closure thus resulting in a similar deformation such that the flip open lid will not stay in its closed position. This, of course, my result in the spillage of the contents of the container or it may result in the degradation of the contents.
There has long been a need for a flip open, screw-on closure that better resisted deformation during the capping operation, particularly if the closure was screwed onto the container with more torque than was necessary. There has also been a need for such a flip-open closure where the lid will remain secured in its closed position during shipping, and while the product is displayed on store shelves and is used by the consumer.